This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A268206 #4 Jan 28 2016 16:05:27 %S A268206 4,81,3600,324900,48441600,10817248036,3377332413504,1404654302923524, %T A268206 750581746192664100,501056831514160707984,408622467650013146382336, %U A268206 399732806541644129265761569,461983489514281294192077209856 %N A268206 Number of 2Xn 0..n arrays with every repeated value in every row and column greater than the previous repeated value. %C A268206 Row 2 of A268204. %H A268206 R. H. Hardin, <a href="/A268206/b268206.txt">Table of n, a(n) for n = 1..26</a> %e A268206 Some solutions for n=3 %e A268206 ..0..1..1....1..3..1....3..1..2....2..3..1....3..2..2....3..0..1....2..2..0 %e A268206 ..1..2..1....3..0..1....3..0..3....1..2..0....2..1..3....0..1..0....2..1..2 %Y A268206 Cf. A268204. %K A268206 nonn %O A268206 1,1 %A A268206 _R. H. Hardin_, Jan 28 2016